Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair

Goal of the Study?

In this study ¹, the goal is to answer how physical exercise promotes tissue healing in bone, muscle, tendon, and cartilage.

 

Why are they doing this study?

Physical therapists and other clinicians prescribe exercise to address muscle tears, non-inflammatory arthropathies and controlled loading after injuries. This practice is in line with systematic reviews and controlled trials that demonstrate how exercise and movement can benefit patients with a range of musculoskeletal problems. However, in this short article, the authors focus on what happens at the tissue level to promote the repair and remodelling of tendon, muscle, articular cartilage, and bone. They argue that mechanotransduction, which is the physiological process where cells sense and respond to mechanical loads, is the term that best describes this process. 

 

What was done?

The authors began with a literature search for the earliest reference to mechanotransduction, finding 2441 citations in Medline. However, the term is not found in the current Oxford English dictionary and lacks a formal definition. Therefore, they suggest that a useful definition of the term would be “the processes whereby cells convert physiological mechanical stimuli into biochemical responses.” They then break down the process of mechanotransduction into three parts: mechanocoupling (the physical load), cell to cell communication (the communication throughout the tissue) and cellular response (the “tissue factory”).

To determine if mechanotherapy is taught in physical therapy programs, they formed international and intergenerational focus groups. The informal results suggest that mechanotransduction was not being taught in physical therapy education programs. To address this deficiency, they re-introduce the term ‘‘mechanotherapy’’ to cover situations where therapeutic exercise is prescribed to promote the repair or remodelling of injured tissue. Using this term, they then summarize clinical studies that have shown or implied a potential for mechanotherapy to promote healing of tendon, muscle, cartilage, and bone. 

 

What did they find?

Their review of clinical studies found that exercise has a beneficial response to controlled loading after injury for tendons, muscles, cartilage, and bone. For example, one study on tendons demonstrated that tendons with Achilles tendinosis treated with exercise showed near-normal structures after almost four years. Similar findings are demonstrated with the application of mechanotherapy for muscle injury. Clinical studies illustrated that the benefits of loading include better alignment, faster regeneration, and less atrophy.  

 

Why do these findings matter?

Patients are often prescribed exercise as a form of treatment for a variety of musculoskeletal issues. Therefore, it is important to understand better how mechanotherapy can benefit patients’ healing and its value for physical therapy.